// Copyright (C) 2003-2010 Xtensive LLC.

// All rights reserved.

// For conditions of distribution and use, see license.

// Created by: Dmitri Maximov

// Created:    2008.01.11



using System;

using Xtensive.Core.Internals.DocTemplates;

using Xtensive.Storage.Model;



namespace Xtensive.Storage

{

  /// <summary>

  /// Defines root type of hierarchy of persistent types.

  /// </summary>

  /// <remarks>

  /// <para>

  /// All entities in your model can be divided into one or more persistent hierarchies. 

  /// Persistent hierarchy is a set of entities, that are inherited from one entity class(hierarchy root) 

  /// and have the same key structure. Hierarchy root entity should be marked by this attribute.

  /// </para>

  /// <para>

  /// Persistent hierarchies can use diffirent inheritance schemas, e.g. all instances of hierarchy can be 

  /// stored in a single table or different tables should be crated for each entity class. Inheritance schema

  /// can be specified in <see cref="InheritanceSchema"/> property.

  /// </para>

  /// </remarks>

  /// <example>In following example two persistent type hierarchies are declared.

  /// Inheritance shema is specified for documents hierarchy.

  /// <code>

  /// [HerarchyRoot]

  /// public class Product : Entity  { ... }

  /// 

  /// [HerarchyRoot(InheritanceSchema = InheritaceSchema.ClassTable)

  /// public class Document : Entity  { ... }

  /// 

  /// public class Invoice : Document { ... }

  /// </code>

  /// </example>

  [Serializable]

  [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]

  public sealed class HierarchyRootAttribute : StorageAttribute

  {

    /// <summary>

    /// Gets the inheritance schema for this hierarchy.

    /// </summary>

    /// <remarks>

    /// Persistent hierarchies can use diffirent inheritance schemas, e.g. all instances of hierarchy can be 

    /// stored in a single table or different tables should be crated for each entity class.

    /// </remarks>

    public InheritanceSchema InheritanceSchema { get; set; }



    /// <summary>

    /// Gets or sets a value indicating whether key should include TypeId field.

    /// </summary>

    /// <remarks>

    /// TypeId can be included into entity Key for some specific optimization purposes.

    /// Default value is <see langword="false" />.

    /// </remarks>

    public bool IncludeTypeId { get; set; }





    // Constructors



    /// <summary>

    /// <see cref="ClassDocTemplate.Ctor" copy="true"/>

    /// </summary>

    public HierarchyRootAttribute()

      : this(InheritanceSchema.Default)

    {

    }



    /// <summary>

    /// <see cref="ClassDocTemplate.Ctor" copy="true"/>

    /// </summary>

    /// <param name="schema">The inheritance schema for the hierarchy.</param>

    public HierarchyRootAttribute(InheritanceSchema schema)

    {

      InheritanceSchema = schema;

    }

  }

}